Page 736 - Advanced Organic Chemistry Part B - Reactions & Synthesis

712 cyclization, a copper co-oxidant is not needed. The pyridine is evidently involved in
accelerating the oxidation of Pd(0) by O . 111
2
CHAPTER 8
)
Reactions Involving (CH 2 n CH (CH )
2 n
Transition Metals 3 Pd(OTf) 2 CH CH 2
CH 3
OH O , pyridine O CH 3
2
n = 1,2
Cyclizations of this type can be carried out with high enantioselectivity using a chiral
bis-oxazoline catalyst.
CH 3 Pd(OTf) 2 O
CH 3 catalyst A CH H
benzoquinone 3 Ph N N
O CH 3 Ph
CH 3 H
OH
O
CH 2
61% yield, 97% e.e.

catalyst A
Ref. 112
A deuterium-labeling study of a reaction of this type demonstrated syn stereoselectivity
in both the oxypalladation and -elimination, which indicates that the cyclization occurs
by internal migration, rather than by an anti nucleophilic capture. 113 This particular
system also gives products from double-bond migration that occurs by reversible
Pd(II)–D addition-elimination.
D
D
H
H D D
Pd II
II
OH Pd II O Pd O
O
D
Pd II

O
O

8.2.1.2. Nucleophilic Substitution of -Allyl Palladium Complexes. -Allyl
palladium species are subject to a number of useful reactions that result in allylation
of nucleophiles. 114 The reaction can be applied to carbon-carbon bond formation
using relatively stable carbanions, such as those derived from malonate esters and
-sulfonyl esters. 115 The -allyl complexes are usually generated in situ by reaction
of an allylic acetate with a catalytic amount of tetrakis-(triphenylphosphine)palladium

111 R. M. Trend, Y. K. Ramtohul, E. M. Ferreira, and B. M. Stoltz, Angew. Chem. Int. Ed. Engl., 42,
2892 (2003).
112
Y. Uozumi, K. Kato, and T. Hayashi, J. Am. Chem. Soc., 119, 5063 (1997).
113
T. Hayashi, K. Yamasaki, M. Mimura, and Y. Uozumi, J. Am. Chem. Soc., 126, 3036 (2004).
114 G. Consiglio and R. M. Waymouth, Chem. Rev., 89, 257 (1989).
115
B. M. Trost, W. P. Conway, P. E. Strege, and T. J. Dietsche, J. Am. Chem. Soc., 96, 7165 (1974);
B. M. Trost, L. Weber, P. E. Strege, T. J. Fullerton, and T. J. Dietsche, J. Am. Chem. Soc., 100, 3416
(1978); B. M. Trost, Acc. Chem. Res., 13, 385 (1980).